Part of studying environmental health is accurately measuring people’s exposure to pollutants and other factors in the environment. This is called exposure science, and the latest developments in this research were shared Oct. 15-19 at the 2017 International Society of Exposure Science (ISES) meeting in Research Triangle Park, North Carolina.
In her plenary address, longtime NIEHS grantee Mary Wolff, Ph.D., from the Icahn School of Medicine at Mount Sinai, encouraged her fellow scientists to improve measurement of exposure to chemicals and other relevant factors. She called this consequential exposure science.
“We should aim to measure something that improves people’s lives,” Wolff said.
She stressed that physiologic factors such as age, sex, and body mass index (BMI) should be considered when calculating pollutant exposures and potential health effects. For example, BMI affects exposure to polychlorinated biphenyls (PCBs). These pollutants, which are stored in body fat, are reasonably anticipated to be human carcinogens by the National Toxicology Program.
Wolff said that shortly after exposure to PCBs, lean people have higher exposure levels than people with a higher BMI. As time from exposure elapses, people with higher BMIs will have higher exposure levels.
Wristbands, vacuums, hand wipes, and backpacks
Much of the conference was focused on new tools for measuring exposure to environmental pollutants. In California’s Salinas Valley, adolescent Latina girls are using wristbands to measure pesticide levels in their homes, as part of the Chamacos Of Salinas Evaluating Chemicals in Homes and Agriculture (COSECHA) study. The wristbands were developed by NIEHS grantee Kim Anderson, Ph.D., from Oregon State University.
By comparing pesticides absorbed by the wristbands with home characteristics, the COSECHA study found that home pesticide levels are related to having crops less than 100 meters from the home, windows open, and carpet in the home.
Heather Stapleton, Ph.D., from Duke University, uses vacuums and hand wipes to measure toddlers’ exposure to house dust that contains chemicals used to soften plastic, called phthalates. Levels in hand wipes had the strongest correlation to phthalate measurement in the toddlers’ urine.
Her team also reported a strong association between vinyl flooring in homes and toddler phthalate exposures. Phthalates are suspected to disrupt normal hormone function in the body, causing a range of potential health effects.
NIEHS-funded researchers at Johns Hopkins University measured how air pollution affected asthmatic children in Baltimore by giving the children backpacks to wear. As the children moved about the city, equipment in the backpacks measured air levels of tiny particles produced by fossil fuel combustion.
Reducing exposure — smart design, community input
New scientific knowledge informs ways to reduce exposures. John Durant, Ph.D., from Tufts University, worked with communities, architects, and planners to reduce air pollution exposure at parks near freeways in Boston. The collaborators designed solutions, including a baseball backstop that blocks airflow from the freeway. They also worked with housing developers to make changes such as moving apartment building air intakes away from the roadway.
Robert Gunier, Ph.D., from the University of California at Berkeley, said the COSECHA study found that using a doormat is a simple step that can reduce home pesticide exposures. They now recommend the simple strategy to Salinas Valley families.
Data collected by first responders after floods in Texas is helping to identify safe practices during emergency response, according to Cornelius “Kees” Elferink, Ph.D., director of the NIEHS-funded Environmental Health Sciences Core Centers at the University of Texas Medical Branch, Galveston. These efforts are part of the NIEHS-led Disaster Research Response (DR2) program.
“Starting as a basic scientist, my outlook really grew through my involvement in this research,” said Elferink. “I’m such a strong proponent of community-based participatory research now.”
(Virginia Guidry, Ph.D., is a technical writer and public information specialist in the NIEHS Office of Communications and Public Liaison and a regular contributor to the Environmental Factor.)